Solar radiation is highly intermittent and its use for demand-sensitive
electricity generation requires energy storage. Storing large amounts
of solar-produced electricity is challenging and has been a highly sought
after goal. High-temperature solar thermal energy storage can be deployed
as an alternative enabling technology for matching solar radiation
availability and electricity demand.

This project aims at developing a novel high-temperature thermochemical
energy storage syst em for dispatchable and efficient concentrating solar
power generation via combined power cycles. The proposed approach is based
on the manganese-oxide redox cycle in a system involving two
fluidised-bed reactors (Fig. 1), one for solar-driven
high-temperature endothermic reduction and one for non-solar
lower-temperature exothermic oxidation.
We will develop stable and durable redox materials promising high reaction
rates, and development of a solar reduction reactor prototype promising
high efficiency. The solar reactor is a novel beam-up concept that allows
for suppression of convective heat losses from a down-facing receiver
cavity, effective and well-controlled fluidisation of the redox material
due to a symmetric vertical orientation, and high optical efficiency
due to the symmetric field layout around the receiver.

The proposed technology allows for higher operating temperatures,
and thus higher efficiencies of the power cycle,
compared to non-thermochemical storage systems.
It has the potential for efficient and fast-response high-energy density
storage in the solid oxide material.